Up grading an I Mac OS X version 10.9.5

What year model is the iMac..?

see > Identify your iMac model - Apple Support

Apple not longer provides updates or downloads for Mavericks 10.9

So depending on the year model iMac.

What you need is El Capitan 10.11, High Sierra 10.13 or Catalina 10.15 if the iMac supports it.

see > How to download and install macOS - Apple Support

That depends on the iMac year of release.

You can find that by click the Apple menu  > About This Mac.

It will have to be a mid-2011 or newer to run 10.11 El Capitan and that may or may not get you online and connected to the Canon website to download drivers.

To upgrade your OS, you can find links to older versions of Mac OS X here: How to download and install macOS - Apple Support

Follow the guidance in the section 'Use a web browser for older versions' of that document for downloading and then installing the older OS. Use Safari for the download if you can. Other browsers may not work. That point may be moot however because the OS version you have, 10.9 Mavericks, is pretty limited on today's internet.

If you cannot get that Mac to connect and download drivers, you might take advantage of another newer Mac to get the files you need and then use a flash drive to transport them into the old iMac.

Canon Support – PIXMA TR4720

Canon Knowledge Base – PIXMA TR4720 Easy Wireless Connect Setup - Mac OS

There are downloads for many versions of Mac OS X / macOS, but I did not see a "Master Setup" download for any version of macOS prior to High Sierra. The "Product Info" page says the printer is compatible with Big Sur through Tahoe, without mentioning any earlier macOS versions.

One piece of good news iis that this printer has completed AirPrint certification requirements.

About AirPrint - Apple Support

"To use an AirPrint-enabled printer, you don't need to install additional drivers or other software."

You keep beating me to the post button this evening.

😆

Well I'm shutting down for the evening, so you have the conn, my friend.

The author is in good hands. 👍🏽

Yeah' it's 9:23 PM PST here and I'm thinking about calling it a night.